Rates Of Deep Sternal Infection Research Articles

Bilateral Versus Single Internal Thoracic Artery Grafting in Diabetic and Older Patients with Triple Vessel Disease: Analysis of a Multicentre Database

Background: Use of bilateral internal thoracic arteries (BITA) is associated with improved long-term survival compared to a single internal thoracic artery (SITA), despite its low penetrance in clinical practice. Such a strategy is arguably less desirable in patients who are older and those who have diabetes, due to a perceived increase in perioperative risk with limited prognostic gain associated with BITA. As such, we sought to examine the prevalence and outcomes of BITA use in this subset of patients. Methods: From 2001 to 2013, 25,900 patients at 28 centres with three-vessel coronary disease underwent primary isolated coronary artery bypass grafting (CABG) using at least a single ITA. BITA use was 12% overall, 15% (n = 2379) in those under 70 years of age (n = 15879) and 6.6% (n = 661) in those over 70 years (n = 10016), p < 0.001. Amongst those with diabetes (n = 7948), BITA use was 7.4% (n = 590). Separate propensity-score matched analyses were conducted for the following subsets: 1) over 70 years of age, 2) under 70 years of age and 3) those with diabetes (treated with either oral agents or insulin). The National Death Index was used to determine survival. Results: In the propensity-score matched analysis comparing single versus bilateral ITA in those over 70 years of age (619 matched pairs), there were comparable rates of sternal infection (1.1% vs. 2.1%, p = 0.26) but a trend towards higher 30-day mortality (SITA: 1.1% vs. BITA: 2.7%, p = 0.064). Survival at 8 years was also comparable (SITA: 74 ± 3.2% vs. BITA: 72 ± 3.1%, p = 0.88). In the analysis amongst patients under 70 (2193 matched pairs), 30-day mortality was similar (SITA: 0.3% vs. BITA: 0.5%, p = 0.48), however BITA patients experienced higher rates of sternal infection (0.8% vs. 1.8%, p = 0.008). Survival at 8 years was nonetheless comparable (SITA: 92 ± 1.3% vs. BITA: 92 ± 0.9%, p = 0.29). Amongst patients with diabetes (564 matched pairs), 30-day mortality was comparable (SITA: 0.9% vs. BITA: 2.0%, p = 0.21), as was sternal infection (2.5% vs. 4.1%, p = 0.18). Survival was similar at 8 years (BITA: 84 ± 2.7% vs. SITA: 78 ± 3.8%, p = 0.47). Conclusions: Use of bilateral internal thoracic arteries remains relatively uncommon, especially in older patients and those with diabetes. It is associated with increased rates of deep sternal infection although early mortality was comparable. Mid-term survival was comparable between patients receiving either single or bilateral internal thoracic artery grafting. As such, the benefit of bilateral ITA grafting may lie only in those with longer life expectancies.

Sternal cables are not superior to traditional sternal wiring for preventing deep sternal wound infection.

Deep sternal wound infection is a devastating complication of cardiac surgery. In the current era of increasing patient comorbidity, newer techniques must be evaluated in attempts to reduce the rates of deep sternal wound infection. A randomized controlled trial comparing sternal closure with traditional sternal wires in figure-8 formation with the Pioneer cabling system® from Medigroup after adult cardiac surgery was performed. A total of 273 patients were enrolled with 137 and 135 patients randomized to sternal wires and cables group, respectively. Baseline characteristics between the two groups were well balanced. Deep sternal wound infection occurred in 0.7% of patients in the wires group and 3.7% of patients in the cables group (absolute risk difference = -3.0%, 95% confidence interval: -7.7 to 0.9%; P = 0.12). Patients in the cables group were extubated slightly earlier than those in the sternal wires group postoperatively (9.7 vs 12.8 h; P = 0.03). There was, however, no significant difference in hospital and follow-up pain scores or analgesia requirements. The Pioneer sternal cabling system appears to facilitate early extubation after adult cardiac surgery, but it does not reduce the rate of deep sternal infectionAustralian New Zealand Clinical Trials Registry: ANZCTR-ACTRN12615000973516.

Intensive Insulin Therapy Has No Effect on Mortality and Morbidity in Cardiac Surgery Patients: A Meta-Analysis

Introduction: Optimal glycemic control in cardiac surgery patients remains a laudable but confusing practice. Existing studies have primarily employed two maintenance strategies using either intensive insulin therapy (IIT) (maintain glucose p = 0.628), ICU LOS (MD = -0.073 days, 95% CI = -0.324 to 0.178; p = 0.568), or hospital LOS (MD = 0.269, 95% CI = -2.158 to 2.696; p = 0.828). No difference in AF rates (RR = 0.887, 95% CI = 0.681 to 1.155; p = 0.375) or deep sternal infection (RR = 0.985, 95% CI = 0.357 to 2.720; p = 0.977) were observed. Conclusion: IIT targeting blood sugar levels of 80 - 120 mg/dl have no effect on perioperative outcomes in cardiac surgery patients. IIT is associated with similar mortality, ICU LOS, hospital LOS, AF rates, and deep sternal infection rates compared to more liberal glycemic strategies. IIT should not replace CIT as the standard of care in cardiac surgery patients.

Bilateral internal thoracic artery grafting in insulin-treated diabetes

We sought to assess the risk and late outcome of bilateral internal thoracic artery grafting in eligible insulin-treated diabetic subsets. 147 insulin-treated diabetic patients undergoing arterial revascularization were grouped as: skeletonized bilateral internal thoracic artery (n = 83) or internal thoracic artery-radial artery (n = 64). Chronic lung disease or overweight and female constituted exclusion criteria for bilateral internal thoracic artery grafts. Patients who had bilateral internal thoracic artery grafts were younger and comprised fewer females. Left-sided bilateral internal thoracic artery configurations were predominantly applied. Despite mean hemoglobin A1c of 8.0% ± 1% (range, 7%-13.5%) respective rates of deep sternal infection in bilateral internal thoracic artery and radial artery patients were 1.2% and 0%; superficial wound infection occurred in 3.1% and 3.6%, respectively. One sternoplasty was performed. Bilateral internal thoracic artery grafting did not correlate with sternal complications (odds ratio = 2.24, 95%CI: 0.56-8.95, p = 0.256). Of the radial artery conduits, 98% were adequate, and procurement-site complications occurred in 3.1%. Follow-up was 2-58 months (median, 25 months). Five-year survival was comparable in the 2 groups (p = 0.360). Bilateral internal thoracic artery grafting did not reduce late major adverse cardiac events (p = 0.729) or late mortality (p = 0.384). Skeletonized bilateral internal thoracic artery grafts can be used with acceptable risk in a substantial portion of insulin-treated diabetic patients, so it should not be automatically denied, but the choice of such grafts is not associated with midterm cardiac benefits.

Effect of Obesity on Early Morbidity and Mortality Following Cardiac Surgery

The prevalence of obesity in most developed nations, including Australia, continues to rise and represent an increasing public health concern. Obesity has been considered a major risk factor in patients undergoing cardiac and other major surgery. We retrospectively analysed prospectively collected data of consecutive patients undergoing cardiac surgery between June 2001 and February 2006 at two Australian public hospitals. Patients were divided into three groups by body mass index (BMI): non-obese (BMI 20-30), obese (BMI>30-40) and morbidly obese (BMI>40). Associations between early mortality and morbidity and obesity were assessed by univariate and multivariate methods. Out of 4053 patients, 85 were excluded for BMI<20. A total of 2743 patients were defined as non-obese, 1136 obese and 89 morbidly obese. There were no significant differences in operative mortality, stroke, pneumonia, new renal failure, atrial fibrillation, prolonged ventilation, reintubation, readmission to intensive care, prolonged length of hospital stay or readmission within 30 days. The morbidly obese group had increased rates of deep sternal infection by univariate (odds ratio [OR] 6.4, 95% confidence interval [CI] 2.1-19.1, p<0.001) and multivariate (OR 13.1, CI 3.4-50.7, p<0.001) analysis. The obese group had a lower rate of re-operation for bleeding by univariate (OR 0.61, CI 0.41-0.91, p=0.01) and multivariate (OR 0.64, CI 0.42-0.99, p=0.04) analysis. Apart from an increased rate of deep sternal wound infection, obesity is not associated with early mortality or other post-operative complications. The protective effect of obesity on re-operation for bleeding requires further study.

Prevention of Postoperative Mediastinitis

In a prospective study of more than 4,000 consecutive patients who underwent any cardiovascular procedure requiring sternotomy incision in a 650-bed tertiary care hospital, a gradual increase in deep sternal infections from 0.8% in 1995 to 2.1% in 1999 was noted. By using a Plan-Do-Check-Act process improvement model, several interventions to decrease the infection rate were planned and implemented based on hypotheses generated from the characteristics of infected patients. These interventions included chlorhexidine preoperative shower, discontinuation of shaving, administration of antibiotics in the holding area, segregation of instruments, and implementation of an insulin protocol. Findings included a decrease in deep sternal and leg infections after implementation of these interventions. Deep sternal infection rates decreased from 2.1% to 1.5% and leg infection rates, from 1.93% to 0.47%. Results were not statistically significant but were clinically relevant. Furthermore, a total of $200,000 was achieved in cost savings in 1 year.

Impact of active monitoring of infection control practices on deep sternal infection after open-heart surgery

Background. Deep-sternal infection is a devastating complication after open-heart surgery. However, the association between infection control practices and deep-sternal infection rates is unclear. Methods. To identify contributors to increased deep-sternal infection rates in our institution, consecutive open-heart surgery patients were prospectively studied during two periods (75 and 40 days), including 66 and 40 patients, respectively. Active monitoring including 149 infection control practices was performed in the operating room and intensive care unit. End-points were deep-sternal infection rates and their relation to infection control practices. Results. Mean age was 62 ± 11 years and 68% were males. Coronary bypass was performed in 82%. Clinical and surgical features were comparable, except that patients in period 2 were more likely to have heart failure (15% vs 1.5%, p = 0.01) and had a longer mean duration of surgery (277 vs 217 minutes, p < 0.005). Only 57 practices (38%) were adequately performed. The main categories showing inadequate practices were disinfection, traffic, hand-washing, and surgical attire of nonscrubbed personnel, anesthesiologists, and pump technicians. Many categories showed a statistically significant improvement between periods. Deep-sternal infection rates in prestudy and poststudy periods were 10% and 2.8%, respectively ( p = 0.007). Conclusions. Active monitoring among personnel involved in open-heart surgery resulted in a significant and sustained decrease in deep-sternal infection rates, through modification of human behavior and improvement of performance standards, probably mediated by the Hawthorne effect. Periodic active monitoring may be a valuable tool to achieve and even sustain such a decrease with tremendous implications on morbidity, costs, and quality of care.

Incidence of deep and superficial sternal infection after open heart surgeryA ten years retrospective study from 1981 to 1991

Between January 1981 and December 1991, 4137 adult patients underwent various cardiac procedures via a median sternotomy under cardiopulmonary bypass. The overall infection rate was 1.33%, including superficial wound infections (SWI) (1.18%) and deep sternal infection (DSI) (0.145%). Pericardial and retrosternal suction drains with a vent allowed a better drainage of blood and serosities and probably contributed to our low DSI rate. Eleven factors predisposing to infection were evaluated by Fisher's exact test. Only the operative urgency (P = 0.006), reexploration for bleeding (P = 0.00001) and preoperative renal failure (P = 0.0005) were statistically significant. Twenty of our infected patients had no risk factors for infection. When the risk factors described in the literature were applied to our infected patients, only one had no risk factor.